Micrometer calipers



H. F. BUTTS MICROMETER CALIPERS April 9, 1957 2 Sheets-Sheet 2 Filed Oct. 14,1955

INVENTOR.

HOMER. F. BUTTS MICROMETER CALIPERS Homer F. Butts, Grand Rapids, Minn.

Application October 14, 1955, Serial No. 540,365

2 Claims. (Cl. 33-148) This invention relates to an improved combination calipers and micrometer. I

nited States Patent '0 An important object of the invention is to'provide a Y practical and efficient device of this kind, one of whose arms is relatively stationary and includes a handle and carries a reading dial, its other arm being movable, and means for locking the movable arm in selected positions, the said means being positioned close to the handle for easy operation by the hand of the operator holding the handle.

Another object of the invention is to provide improved and more accurate operating means between the arms and the dial mechanism which is simple and durable.

Other objects and advantages will appear from the following description, and from the annexed drawings in which like reference characters designate like parts throughout the several views and wherein:

Figure 1 is a side elevational view of a caliper in accordance with the present invention, the arms being in closed position in full lines and in open position in dotted lines;

Figure 2 is a top plan view;

Figure 3 is a bottom plan view;

Figure 4 is an enlarged fragmentary section on line 44 of Figure 1;

Figure 5 is a transverse section on an enlarged scale, on line 5--5 of Figure 1;

Figure 6 is a section on line 66 of Figure 5;

Figure 7 is a plan sectional view of the dial on line 7--7 of Figure 5, and

Figure 8 is an exploded perspective view of the complete device.

Referring to the drawings in detail, the reference numeral 10 designates a handle portion on the inner end of a flat portion 12 on the inner end of an elongated laterally curved portion 14 having at its free end a workengaging tip 16. On the upper edge of the portion 12 (Figure 8) is a projection 13 having a notch 15 at whose upper end is an arcuately bowed bridge 15'.

The portions 10, 12, 14, and the tip 16 constitute a relatively stationary caliper arm 17. A movable caliper arm 17 is substantially shorter than the arm 17 and includes a flat sector portion 18 positioned at one side of the stationary arm portion 12, the sector portion having on its outer end an elongated laterally curved portion 20 having a tip 22 extending toward the tip 16 for engagement with a work piece (not shown) to be measured therebetween. Connecting the arms for relative pivotal movement is a screw 24 having a smooth surfaced shank portion 25 extending through a center hole 27 in the sector portion 18 of the movable arm, and a reduced, threaded terminal 26 engaged in a threaded hole 29 of portion 12 of the stationary arm 17.

The sector portion 18 of the movable arm has an arcuate series of gear teeth 30 on its inward side meshing with a pinion 32 positioned in the notch 15. In a manner to be presently described, pinion 32, disposed at the inner, smaller end of a tapered dial casing 34 rotates a pointer 38.

The sector portion 18 has an arcnate slot 40 concentric with the teeth 30. Sliding in the slot 40 is a reduced part 42 (Figure 4) of a washer 44. A screw 48 extends through the washer and is threaded in an opening 49 in the portion 18. The head 51 of the screw 48 seats in the countersunk outer end 53 of a hole 55 in a locking disc 50 having a circumferential series of radial teeth 57 arranged to engage between similar teeth 59 of another locking disc 52 integrally formed on a radial arm 54 constituting a locking handle. Disc 50 is engaged with the screw 48 against rotation relative to the screw.

Locking of the arms 17 and 17' in selected positions is effected by a throw of handle 54 in a direction such that the teeth of the locking discs 50 and 52 ride over one another in a cam action effective to bias discs 50, 52 away from one another in a direction axially of screw 48. As a result pressure is exerted by Washer 44 against sector portion 18 to bind the sector portion 18 against the arm 17. Further, the sector teeth 30 are bound against those of pinion 32 to effectively lock the arms 17 and 17' in a selected setting.

To facilitate opening and closing of the arms, the stationary arm 17 includes'a depending forwardly curving finger piece 56.

Referring to Figure 5, the dial casing 34 is formed with an upwardly facing recess 57 into which extends a shaft 58 secured to pinion 32. The shaft 58 extends through a sleeve or bushing 60 and within the recess 57 is secured to a pointer 38.

As shown in Figures 5 and 6, one side of the shaft 58 and bushing 60 engage in the concavity of the bridge 15 and the other side thereof engages a portion 61 of the dial casing (Figure 6). Screws 62 connect the bridge 15 to the portion 61 of the dial casing.

A fiat spiral spring 64 in the dial casing recess 57 has one end connected to the shaft 58 and its other end anchored to the wall of the recess 57 to bias the shaft 58 and the pointer 38 toward a zero setting with the arms 17 and 17' in a closed position. In the recess 57 above the spring is fixed a dial 66 having circular scales 68 on its upper face. These scales are arranged concentrically. The scales having the graduations 1-2-3-4-5 provide for a micrometer reading. Each graduation l-2-3-4-5 provides for a micrometer reading. Each graduation on the scale marked 5 indicates five thousandths of an inch, and each mark 1, 2, 3, and 4 indicates one thousandth of an inch. In taking a reading, the number of graduations passed by the pointer 38 are totalled, and to the total is added the number to which the pointer is moved on an appropriate inner scale, 1, 2, 3, or 4. Thus, if the pointer passes three graduations on scale 5 the measurement fifteen thousandths of an inch is proper, and if the pointer passes one graduation on scale 1 the total measurement would be sixteen-thousandths of an inch. If the pointer were to move beyond one graduation on the second scale the total would be seventeen-thousandths of an inch.

The caliper reading is taken on an innermost scale 70, suitably graduated.

Whenever the arms 17 and 17' are spread to take a dimension of a workpiece, the pinion 32 will be rotated by the sector gear, and the pointer 38 will traverse the dial face 66 to the location at which the reading is to be taken.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in apsmas construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. In a caliper, a relatively stationary caliper arm and a movable arm, said caliper arms having outer ends provided with work-engaging portions and inner ends, said stationary caliper arm being substantially longer than said movable arm and having a handle on its inner end, said stationary arm having an intermediate portion located between the outer and inner ends, said movable arm having a sector portion on its inner end, said sector portion and said intermediate portion having facing sides which are engaged, pivot means traversing said sector portion and said intermediate portion, a dial casing mounted on and projecting upwardly from said intermediate portion, a pointer shaft journalled in said casing, said shaft having an upper end provided with a pointer and a lower end, an operating means operatively connecting .said sector portion and the lower end of the shaft, said operating means comprising a pinion on the lower end of the shaft and sector teeth on said sector portion meshed with the pinion, said sector portion having an arcuate slot concentric with said sector teeth, a screw passing through and having the intermediate portion slidably supported in said slot with one end secured to the intermediate portion of said stationary arm, and interlocking discs operatively connected to said screw adjacent the other end and operable to lock the movable arm to the stationary arm.

2. In a caliper, a relatively stationary caliper arm and a movable caliper arm, said caliper arms having outer ends provided with work-engaging portions and inner ends, said stationary caliper arm being substantially longer than said movable arm and having a handle on its inner end, said stationary arm having an intermediate 7 portion located between its outer and inner ends, said movable arm having a sector portion on its inner end, said sector portion and said intermediate portion having facing sides which are engaged, pivot means traversing said sector portion and said intermediate portion, a dial casing mounted on and projecting upwardly from said intermediate portion, a pointer shaft journalled in said casing, said shaft having an upper end provided with a pointer and a lower end, and operating means operatively connecting said sector portion and the lower end of the shaft, said operating means comprising a pinion on the lower end of the shaft and sector teeth on said sector portion meshed with the pinion, said sector portion having an arcuate slot concentric with said sector teeth, a screw having one end secured to said intermediate portion and another end provided with a head, said screw extending laterally outwardly from the facing side of said intermediate portion and being passed through said slot, inner and outer locking discs on said screw between said sector portion and the head of the screw, said outer locking disc being fixed to the screw against rotation relative to the screw, said locking discs having facing sides provided with interengaged radial cam teeth, and said inner locking disc having a radial handle.

References Cited in the file of this patent UNlTED STATES PATENTS 233,421 Keiper Oct. 19, 1880 654,370 Wahrer a- July 24, 1900 1,317,708 Kaplan Oct. 7, 1919 1,385,910 Fox July 26, 1921 1,621,778 Haglund Mar. 22, 1927 1,829,698 Zajtman Oct. 27, 1931 1,849,959 Schneider Mar. 15, 1932 

